Symmetries and Lagrangian time-discretizations of Euler equations

Alexei Penskoi (penskoi@crm.umontreal.ca)
Centre de Recherches Mathematiques
Université de Montréal
C. P. 6128 Succ. Centre-Ville
Montréal (QC) H3C 3J7 Canada

Abstract

In late 80s - early 90s J. Moser and A. P. Veselov considered Lagrangian discrete systems on Lie groups with additional symmetry conditions imposed on Lagrangians. They observed that such systems are often integrable time-discretizations of integrable Euler equations on these Lie groups. In recent papers we studied Lagrangian discrete systems with additional symmetry requirements on certain infinite-dimensional Lie groups. We will discuss some interesting properties of these systems.